Accurate measurements of animal feed intake can greatly improve the efficiency of animal agriculture. Intake measurements can be used along with measurements of weight gain and/or milk production to identify individual animals in a herd that are more efficient in converting feed into useful products such as meat or milk. Intake measurements can also be used to identify sick animals during critical transitions. In beef cattle, the transition from weaning to grazing and the transition from grazing to feedlot finishing are both critical times when animals can be vulnerable to problems that affect long term health and productivity. In dairy cows, the transition from the dry period to the period of high milk production is an especially critical time when early indications of health problems can determine the animal's milk production and survival. In modern dairies, each year approximately eighteen percent of the animals are culled due to health issues that arose during this transition period. The percentage of the herd that is culled or dies at this stage of lactation has risen from four to five percent in 2005 to over six percent by 2010.
Measurements of individual animal intake can provide the early warning necessary for successful treatment and avoidance of animal losses. However, current commercial systems to monitor individual animal intake are expensive to install, require rigid placement and extensive networking, and are constructed of fiberglass or plastics that are expensive to ship and difficult to clean, e.g., with high-pressure power washing equipment, without damage.
With regard to these current commercial systems, several companies currently market animal feed intake systems, but none of these companies systems have met all the demands of the industry. For example, existing commercial systems typically employ a plastic or fiberglass feed bin, which is placed on a rigid frame containing two support rails onto which are mounted load cells, and these bins cannot typically be washed with high-pressure power washing equipment or with many readily available cleaning solutions.
In existing systems, animals are each equipped with an RFID tag either mounted within a plastic block attached to a collar that is placed around the animal's neck or animals are equipped with a plastic ear tag that is equipped with a passive radio frequency identification device (RFID ear tag). Some systems require a half-duplex tag while other systems can utilize both half-duplex and full duplex tags. These bins are sold in multiple units that are linked through wiring so they can operate without interfering with each other. In operation, typically when an ear tag is read, the weight of the feed bin and its contents is recorded. When the ear-tag ceases to be read, the weight of the feed bin and its contents is again recorded. The loss of weight is then used to estimate intake for that animal for that specific time-period. Some systems attempt to correct for weight that could have been added due to rain or to saliva from the animal being deposited on the feed. Some systems use proprietary methods for calculating weight loss. In one exemplary method, the changes in the beginning weight over a unit of time when an animal is not present is used to estimate the change in the background weight and averaged into the feed intake calculation. However, there is no evidence documented in the scientific literature to indicate that this averaging procedure produces more accurate results such that there is a need for livestock feed systems with control or monitoring devices that more accurately determine intake of each animal feeding at the system.
Some intake systems set a minimum time that the animal must be in position to consume feed, either measured by RFID tag reads or measured independently using an interrupted light beam before a feeding bout is registered and weighed. This time requirement may not be desirable in many applications. Each of these systems transfers data through a wired interface to a data-logger or a computer where data is tabulated for future processing and later display. Connecting each unit together through wiring to create a network is necessary because for these systems independent units operating in close proximity to each other may cause interferences, primarily in the RFID readers, that prevent proper operation of individual units in the network. Hence, such systems can be complex to install and are not typically modular or readily scalable up and down in size.
Feed intake systems generally also include some type of gate or barrier designed to prevent one animal from accessing the feed and another from pushing the first animal out and “stealing” its feed. These gate systems can be as simple as a series of vertical bars placed the appropriate distance apart at the central opening so that only one animal at a time can access the bin. Sometimes a horizontal bar is located on the gate so that the animal must insert its head below the bar to access the feed, and the bar is placed to prevent the animal from tossing the feed ration and/or from quickly backing out if harassed by another animal. Other systems simply include an opening shaped like a keyhole or even just a ‘V” shape so that only one animal can access the feed and that it cannot easily back out without lifting its head. Sometimes intake measurement systems restrict each specific animal to a designated feed bunk. The restricting device is often a Calan Gate (available from American Calan, Northwood, N.H., USA) that will only unlock and swing open when a specific ear tag is read. In some systems, gates that either swing open or that slide upwards from below the feed bin can be added and controlled to provide access to the feed bin by specific animals at designated times of the day for designated periods of time.
In use, residual feed remaining in the feed bunk or bin must be periodically removed. This is because residual feed when contaminated by moisture or saliva can become moldy and otherwise unpalatable. In the current systems on the market, the bins are emptied using a shovel and dustpan to remove the orts. Usually, the whole bin can be tipped up on one side to make this task less difficult. However, individual bins are heavy, and lifting the feed bunks for cleaning in a system with many intake units is an onerous, time-consuming task.
At specified intervals, such as when a new group of animals is to be measured, each bin is also typically thoroughly scrubbed and decontaminated. Plastic bins require hand scrubbing with brushes and thorough rinsing to remove contamination caught in deep scratches or absorbed into the plastic. Fiberglass bins must be carefully scrubbed with a cleaner that does not contain aggressive abrasives, which makes cleaning more difficult. In addition, cleaners are required to decontaminate the often pitted surfaces of the bins from harmful microorganisms and other disease agents. Care must be taken in order to minimize the introduction of difficult to sanitize scratches into plastic and composite materials. Further complicating the cleaning effort, waste material resulting from cleaning and decontamination of intake bins may have to be separated from the normal manure-handling waste-stream. Cleaning is made more difficult because plastic and composite surfaces of current intake monitoring systems are not thermally stable and are, therefore, incompatible with the use of steam for decontamination and cleaning. With existing bins of livestock feed systems, heat and chemicals can accelerate delamination and dimensional instability of feed bins. After extended use, both plastic and fiberglass bin materials exhibit significant cracks, pitting, and surface roughness making decontamination difficult, which may in many cases require replacement of the bins.
The installation of feed intake systems currently in use in the animal industry requires careful planning and extensive infrastructure, and the number and locations of intake feed bunkers or bins must be specified in advance of installation. Typically, cattle must be removed from the pens where the equipment is to be installed. Next, earth must be moved to provide the recommended drainage and a stable platform for concrete forms. Then, concrete forms are built, and concrete is poured. The next step involves installing wiring for electricity and for data collection and transmission and for control functions into a system of conduits that are routed to each unit from a dedicated computer system that is placed remote to the feed bins so as to be in a relatively clean and dry environment with stable power so that this “control and processing” computer can reliably operate without interruption.
Installation further includes installing and routing power and, often, pneumatic lines to each feed bunk. The final step is the installation, calibration, and testing of each feed bunk and of the entire integrated system including weighing systems, animal control systems, data-handling systems, data monitoring and display systems, and auxiliary power stabilization, filtering, and backup systems. It is especially important as part of installation to adjust the timing of the RFID readers so that they do not interfere with one another or with on-site equipment that could produce interfering noise. In several use cases or applications, commercial intake measurement systems were not able to operate in proximity to the other livestock feed systems. For example, some systems use a propriety method to synchronize units that can be incompatible with systems that employ international standards. Therefore, synchronization of the two systems may not be readily attained. After calibration, animals can be reintroduced into the feed pens, and the process of training animals to utilize the feed bunks can begin. This process typically extends over approximately twenty-one days, and the period of actual measurements usually extends seventy-five days or more for each group of animals that is monitored, depending on the purpose of the measurement program.